Color information reading apparatus for reading binary data

Abstract

A color information reading apparatus wherein the apparatus basically comprises an original information reading unit provided with a photoelectric converter element, for scanning an original once with each of first and second light of different colors so as to convert light reflected from the original into electric signals, thereby outputting the converted respective signals in line sequence, an amplifier for amplifying each output from the photoelectric converter element, a bi-level digitizing circuit for representing the output of the amplifier in binary form, a plurality of line memories for storing therein data output from the bi-level digitizing circuit, a threshold level shifting device for changing the threshold level to another for each pixel, a color discriminating circuit for discriminating among colors base on data representing in binary form the signal obtained by scanning the original with the first light and data representing in binary form the signal obtained by scanning the original with the second light, and a color processing circuit for converting the output from the color discriminating circuit into either a white signal or a black signal so as to output the converted signal therefrom when the output of the color discriminating circuit differs from the output of the color discriminating circuit prior to one pixel.

What is claimed is: 
     
       1. A color information reading apparatus comprising: original information reading means for scanning an original once with each of first and second light of different colors so as to convert light reflected from the original into electric signals, thereby outputting the converted respective signals in line sequence;   bi-level digitizing means for representing each output from said original information reading means in binary form;   threshold level shifting means for changing a threshold-level-upon-bi-level-digitizing to another for each pixel when either a signal obtained by scanning the original with the first light or a signal obtained by scanning the original with the second light is converted into a binary level;   color discriminating means for discriminating among colors based on data representing in binary form the signal obtained by scanning the original with the first light and data representing in binary form the signal obtained by scanning the original with the second light; and   color processing means for converting the output from said color discriminating means into either a white signal or a black signal so as to output the converted signal therefrom when the output of said color discriminating means differs from the output of said color discriminating means prior to one pixel.   
     
     
       2. A color information reading apparatus according to claim 1, wherein said threshold level shifting means is used as means for changing the gain of said original information reading means to another. 
     
     
       3. A color information reading apparatus according to claim 1, wherein said threshold level shifting means is used as means for changing the threshold level of said bi-level digitizing means to another. 
     
     
       4. A color information reading apparatus according to claim 1, wherein said threshold level shifting means is used as means for adding a bias value to the output from said original information reading means. 
     
     
       5. A color information reading apparatus according to claim 1, wherein said color processing means includes logical-product operating means for AND-operating the output from said color discriminating means with the output from said color discriminating means prior to one pixel.